Creative design plays a quite important role in mechanical product processing, which affects the mechanical development of all over the country. Much research on the mechanical design is carried on. The paper is mainly based on Yan’s Creative Mechanism Design Methodology, in which the author carries out some research in Type Synthesis based on the Number Synthesis Method. And kinematic chains of eight links and ten joints can be gained from embryo graphs. In the article, the author proposes a systematic method for the creation of a sofa bed. In the process, some rules are brought in, and the original structure is changed for other structures with the same functions but different shapes. At last, many probable schemes different from the original mechanism are obtained. The next step is to choose the most proper scheme in order to carry on the further analysis.